1. Field of the Invention
The present invention relates to an information processing device that enables an application program to use a hardware resource managed by the operating system, and in particular an information processing device capable of suspending and resuming an application program running in multitask processing environment.
2. Description of Related Art
Work that is being carried out by an application program running on an information processing device such as a personal computer may sometimes be temporarily suspended. In such a case, if the application program is left running on the information processing device, the work data at some midpoint may be altered or lost because of accidental manipulation by the user itself or manipulation by other persons who are not using that application program. Therefore, such a situation is undesirable.
In order to solve a problem like this, it has been proposed that the information processing device as a whole be temporarily brought into an unusable state such as a screen-locked/suspended/hibernated state while maintaining the operation state of the application program. Japanese Unexamined Patent Application Publication No. 6-161590 discloses an information processing device capable of hibernating.
Furthermore, as another solution for such a problem, work contents that are processed halfway through the work by an application program may be stored as data in common practice.
When an application program is being executed on an information processing device disclosed in Japanese Unexamined Patent Application Publication No. 6-161590, if the application is to be interrupted, the information processing device as a whole is brought into an unusable state. That is, when a user wants to temporarily stop document creation using a word-processor and to carry out aggregate calculation using a spreadsheet, the entire information processing device is brought to an unusable state even though the user wants to suspend only the work using the word-processor. Consequently, the user cannot carry out the aggregate calculation work using the spreadsheet as well as the work using the word-processor, and thus impairing usability.
Furthermore, when work contents on which an application program has been executed halfway through the work is to be stored as data, only the work contents are stored. Therefore, information about the displayed portion and the display state at the time of the interruption is lost. A user who wants to resume the work has to take trouble such as finding and displaying the displayed portion, and reproducing the work state using his memory, and thus further impairing usability.
In such a case, if the work state in the application program can be also stored as data, it becomes possible to resume the work state at the time of the interruption based on the stored data, so that the user can resume the work without any trouble. However, in recent years, implementation of multitask processing in which two or more application programs are executed in parallel has become common in information processing devices such as personal computers.
In multitask processing environment, there is a possibility that a user reumes a stored application program in a state where a computer resource that was used by the application program before the interruption is being used by other applications at the time of the resumption, and thus causing access conflict for that computer resource and consequently a malfunction of the information processing device.
Accordingly, an exemplary object of the invention is to provide an information processing device that can store an execution state of an application program running on multitask processing environment and resume the application program based on the stored execution state.